Sound-producing diaphragm



Aug. 6, 19%9'. w. H. Km'o SOUND PRODUCING DIAPHRAGI Filed April 15 1926 3 Sheets-Sheet I INVENTOR. M 26% ATTORNEY.

g- 1929- w. H KITTO ,7 ,550

SOUND PRODUC ING DIAPHRAGM Filed April 15. 1926 5 Sheets-Sheet 2 M" INVENTOR.

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6, 2?- w. H. KITTO SQUND PEODUCINQ DIAPHRAGM Filed April 15, 1926 3 Sheets-Sheet Patented Aug. 6, 1929.

UNITED STATES TENT WILLIAM H. .KITCLO, 0F FERNDALE, MICHIGAN.

SOUND PRODUGING DIAPHRAGM.

Application filed April 15, 1926. Serial No. 102,159.

The object of m invention is to produce a sound producing (l eral thin sheets of metal, that maybe readily adapted tosound producing instruments such as radio speaking units, phone receiving sets or the phonograph sounding unit.

Another object is to produce a laminated sound producing disc, comprising thin sheets of different metals, or materials, each capable bined into a single unit to prevent chatter- I in of the disc, or the production of supervi rations producing false tones and squeals.

A further object is to produce a sound diaphragm disc that will greatly enlarge the range of production of clear, distinct tones, ,without distortions,modifications, or squeals, and that is adapted to very low or high tones.

A still further object is to produce a sound speaker cap removed, showing my diaphragm.

.as applied thereto, and its relative position to the operating magnets. I r v Fig. 3, is a plan view of the diaphragm, showing its circular construction and its intermediate disc. I

Fig. 4, is an edge view ofthe assembled disc where the edges'of the laminae are closed, as

-,when installed within theoperating frame.

= Fig. 5, is a sectional view taken on the line .'-5--5- of the Fig. 3, showing the arrange lrnent of the various thin. sheets comprising the diaphragm.

Fig. 6, is also asectional view on the same" line 5-5 of .Fig. 3, where the outer edges of thethin disc sheets are closed together, as

when clamped tightly within the supporting p s iame l iaphragm, formed of scvof different rates of vibrations, and so com-' .producing diaphragm of, several thin plates, so assembled as to allow the application of a,

- of tones which vary in pitch vibrations of the disk started, ,This pr 1 F ig. 7 is a further cross section taken on s the same line 55 of the Fig. 3, illustrating anexaggerated position the diaphragm under vibrations caused by the speaker magnets, showing a straight, fiat center section along which the diaphragm has a tendency to vibrate.

Fig. 8, is an enlarged detailed cross-section, also taken on the line 5-5 of the Fig 3,

illustrating the assembled laminae, having a lubricant placed between the various sheets of material comprising the diaphragm, as it appears when firmly clamped within the speaker frame.

v Fig. 9, illustrates an alternate form of my disc, where same is applied to sound producing, or speaking unit having a fixedqmember attached to the center of the diaphragm, in

stead of operating same by direct influence of electric magnets. r

Fig. 10, is a sectional, view .-takein on line l0-1( of the'Fig 9, showing the central. hollow assembling rivet, providing means for attaching the operating "member- Fi 11, shows the diaphragm applied to a l soun producing unit, having a central op erating member attached thereto.

Fig; 12, illustrates the application of my diaphra to the sounding head of a phonegraph, t 1e same operating by central contact of a vibrating point.

Fig. 13, is an edge view of a diaphragm using'two lamina.

I will'n'ow describe more fully the detailed construction of my device, referring to the drawings and the marks thereon.

In general my device comprises a series of thinplate discs, assembled by packing Q UT same together as leaves, operating as a single unit and forming a laminated rid producingdiaphragin th reby. The i 1 or laminae may be assembled as dr discs,

or by placing a lubricant between the discs.

It is commonly known that when a'disc of thin material is caused vibrate at a high rate of vibration, it will produce sound, as the rat-e of ciple being in common use in telephone radio receivers. The vibrations ofthe dis phragm being caused by mechanical connected thereto, and which is usually eit r directly or indirectly produced by elec magnets operating on the diaphragm, or

a vibrating member attached to the center of the disc. Where the electric magnet operates directly upon the diaphragm disc for producing the vibrations therein, the disc must possess some magnetic properties which are subject to the influence of the operating magnets, while the discs, or diaphragms, which are operated by a connecting vibrating member need not possess any of the magnetic properties therein to make them operative thereby. My laminatedsound producing diaphragm is so constructed and may be made bled by packing together as leaves, and form ing therebyalaminated diaphragm disc which is to be installed and operated as a single unit,

and in the same manner as the single plate diaphragm now in common use, similar to those employed in radio and telephone work. It

is commonly known that every material rigid body possesses adefinite natural rate of body vibrations which will produce sound if thatrate of vibration is set up therein, or" will respond by sound if a like rate of vibrations is set up in near proximity. Likewise, the

single diaphragm disc possesses a note of its own, a definite .individual rate of natural v1- bration. When impinged upon by the sound of a note of its own natural pitch. it will begin to vibrate and continue such vibration at that given rate per minute for an appreciable period of time. Meanwhile, the sounds being desirably produced have passed on to other notes and pitches, so that dissonance ensues, causing false tones, squeals, breaks in sounds and chattering in addition to the normal or desired tones. This inventor has found that by making the sound diaphragm of the laminated construction, and using a different material for each lamina, thereby combining laminae possessing different rates of body vibrations, each acting to prevent,

or destroy the natural body vibration of the adjacent lamina section, and. thereby eliminating the super tones, squeals, or false notes which would otherwise be produced by a homogeneous diaphragm, and that when. my laminated diaphragm is supported in a frame as shown in Figs. 1, 6 and 8, clamping the outer edges of the disc sections together, the range of the laminated diaphragm has been greatly increased, the assembled diaphragm acting as. a single unit, and will respond to mechanical vibrations produced therein, either by magneticforces, or by connecting vibrating members attached directly to the diaphragm, reproducing sound tones corresponding to the rate of Vibration produce-dtherein, in the same manner as a single plate diaphragm, but with a modulated tone. The range of operation being greatly increased and will pass the rate of' the natural body vibrations of each separate lamina without producing any super tones or squeals. Under the special construction of my diaphragm, each lamina -aand -c are tightly stressed over the inclosed lamina -b by the clamping of the cover -3- over the casing 2 of the operating instrument in which the diaphragm is used, as illustrated in Fig. 8. By using the outside section a of copper, the center lamina of iron, and the inner sect-ion -0- of brass, each being of a different material and possessing a different rate of natural body vibration, the diaphragm may be constructed to wholly eliminate the super tones and squeals which would other wise be produced. Other materials may also be used in forming the combinations, either metals, or materials as mica, celluloid or similar materials which is adapted to very thin sheet construction, or various combinations of these materials. It is found desirable to make the center lamina b. of a smaller diameter than the inside lamina cor the outside lamina a, thus providing a means of stressing the laminae to prevent separate vibrations of any single member due to its own special rate of natural body vibration. The outside sections aand c being firmly clamped between the supporting gasket-s ;1 and -5- placed between the cap --3- and casing -2 of the instrument frame. It isalso found that by making the various laminae of different thicknesses of material, each rate of body vibration may also be changed, and like results obtained, although the use of difierent materials for the different lamina is preferred. During the mechanical vibrations of the diaphragm -1, the same becomes'distorted as illus-' trated in Fig. 7 which causes a slight shifting of the adjacent surfaces one on the other, and

which is greatly facilitated by the use of 'a' thin lubricant or grease -6 placed between each lamina section, as illustrated in Fig. 8. The'lubricant 6 also acts asfa lamina itself, modulating the tone of sound produced thereby, and also aids in preventing separate body vlbrations of the sections. If I the diaphragm --1-- is to be used directly under the influence of operating magnets as shownin Figs. 1 and 2 of the drawin s, at

least one of the lamina must be made 0' iron I or some magnetic material, in order to respond thereto for producing the mechanical vibrations therein. However, if the diaphragm 1 is to be used with a tvpe of instrument utilizing vibrating contact member, either '-13- or 14, as illustrated in Figs. 11, and 12, the magnetic properties of any of the laminae is not re uired, the diaphragm being vibrated by mec anical means. The diaphragm is adapted equally as well to use in a phonograph soundlng head -9,

shown in Fig. 12. Should it be used in a sound producin instrument similar to the.

one illustrated in Fig. 11, a .central hollow rivet 13 may be placed through the center of theassembled sections, and tightly riveted therein, providing means for attaching the vibrating arm -13 thereto.

While I have illustrated my laminated for eac securing a different rate of bod vibrations lamina, and therefore combination that is substantially a substitution of parts herein shown or described.

Having fully described my sound producclaim any ing diaphragm, what I claim-as my invention and desire to secure-by Letters Patent is:

A laminated. diaphragm adapted for producing sound vibrations, said diaphragm being made of at least three very thin disc sections, each section of a different kind of material than its adjacent sect-ion and possessing a different rate of natural body vibrations, a thin lubricant placed between each disc section, one of the inner disc sections be1n outer 111C oslng dlSC sections, all packed a single diaphragm.

In witness whereof I sign these specifications.

WILLIAM H, KITTO.

of a smaller diameter than the tightly together and capable of vibrating as 

